• Venture Beat, Friday, March 11, 2011 11:40 AM

RadiumOne this week said it raised $21 million to develop a social-based ad network. "That [is] a lot of capital for an ad-based start-up, but the San Francisco company believes it can deliver superior advertising performance through its patent-pending ShareGraph technology," writes VentureBeat. The ShareGraph technology analyzes how users communicate with their closest connections and then identifies the specific consumers who are most likely to engage with a brand's ads.

The start-up says this works better than traditional behavioral targeting techniques. Also of note, the system lets consumers share ads with friends -- "creating a multiplier effect for advertisers," VentureBeat notes.

Crosslink Capital led the round, along with DFJ Esprit and existing investors, including Adams Street Partners and Trinity ventures. Having now raised $33.5 million, RadiumOne says plans to grow its staff from 80 employees to about 150 by the end of the year.

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